The present invention relates generally to improvements in foldable implement frames and hitches, and specifically to the provision of such a frame which has an unusually wide operating span and a very narrow transport span.
Implement frames and hitches are used to carry a wide variety of implements such as an air-injection planter for corn and other hard kernel grains, rotary hoes, "duck-foot" field cultivators, and the like. It is desirable that such implement frames have a wide span in the work position thereof so that a plurality of rows of crops can be simultaneously cultivated during a single pass. However, when it is time to transport the implement frame from field to field or along a highway, it is desirable that the horizontal extent of the implement frame be small so as to negotiate gates, highway lanes and the like with ease.
One form of standard practice heretofore has been to make the implement frame foldable between an extended working position and a retracted transport position with the addition of transport wheels when the parts are in the transport position. Examples of such prior implements are illustrated in the following U.S. Pat. Nos.: 2,226,586 granted Dec. 31, 1940 to J. P. Seaholm; 2,706,880 granted Apr. 26, 1955 to W. L. Steuerwald; and 2,938,588 granted May 21, 1960 to C. P. Stein. All of these prior art implement frames require the operator to leave his vehicle and manipulate the frame between the transport and working positions, all with a consequent loss of time and effort.
In another form of prior art practice, the implement frame is provided with one hitch point for the working position thereof and a second and different hitch point for the transport position thereof with the addition of the transport wheels. Such an implement is illustrated in U.S. Pat. No. 3,460,630 granted Aug. 12, 1969 to C. B. Richey. This implement frame also requires the operator to not only leave the draft vehicle to place the parts in the transport position or the work position, as the case may be, but also requires the operator to change the hitch point from that illustrated in FIG. 1 of the patent drawings to that illustrated in FIG. 2, with the subsequent movement and repositioning of the draft vehicle. All of this is time consuming as well as being wasteful of the time and energy of the operator.
In still another form of the prior art practice, foldable wings are provided which fold between a work position and a transport position. Examples of such structures are shown in U.S. Pat. No. 3,791,673 granted Feb. 12, 1974 to M. C. Hornung and U.S. Pat. No. 4,137,852 granted Feb. 6, 1979 to R. L. Pratt; a similar machine is also illustrated in West German Pat. No. 2,537,391 granted Feb. 24, 1977 to Rau. None of these prior structures show extending a telescoping main frame rearwardly of the horizontal support frame so as to provide for short coupling between the draft vehicle and the implement frame in the working positions thereof.
In yet other practices, the implement frame for transport is placed upon a trailer or other vehicle in order to facilitate easy transport thereof. Placement of the implement frame on the transport vehicle is a time consuming operation.